Patients of OSAS intermittently repeat a temporally suffocated state (apnea, infrequent breathing) while the pharynx of the upper respiratory tract is obstructed due to a complication of muscle relaxation and obesity and the like during sleep. Therefore, patients of OSAS are suffered from hypertension or disorders in brain blood vessels and cardiac blood vessels. Further, patients of OSAS cannot sleep sufficiently, and therefore, tend to feel drowsy in the daytime and/or tend to lack of concentration or vitality in the daytime. Yet further, when driving a car, patients of OSAS have high chances of causing an accident, a serious accident or the like due to falling asleep at the wheel.
On the other hand, similarly to OSAS, snoring occurs when the respiratory tract's mucus membranes of the pharynx and the like vibrate due to stenosis or obstruction of the upper respiratory tract during sleep. Snoring disturbs not only the sleep of a roommate but also the sound sleep of a snorer oneself, and the snorer tends to feel drowsy in the daytime or tends to lack of concentration or vitality in the daytime.
In view of the above, a variety of proposals have been made in recent years for treating or resolving OSAS or snoring. For example, such proposals include “a method of inserting a tube into the pharynx via a nasal passage (hereinafter referred to as “a tube inserting method” (e.g., Japan Laid-open Patent Application Publication No. JP-A-2009-072581)”, “a method of expanding the pharynx by inserting a tube, to the tip of which a water swelling resin is applied, into the pharynx via a nasal passage, and subsequently, by swelling the water swelling resin using moisture in the periphery of the pharynx (hereinafter referred to as “a water swelling method”, see e.g., Japan Laid-open Patent Application Publication No. JP-A-2009-072581)”, “a method of expanding the pharynx by inserting a tube having an expansion portion in the tip thereof into the pharynx via a nasal passage, and subsequently, by expanding the expansion portion through a user's operation (hereinafter referred to as “an operational expanding method”, see e.g., Japan Laid-open Patent Application Publications Nos. JP-A-2006-204630, JP-A-2009-034384, JP-A-2009-072581, JP-A-2009-072582, etc.)” and etc.